Floors in buildings get dirty with use and must be periodically cleaned, so specialized equipment has been developed for the purpose. In particular, the requirements for floor cleaning in public, commercial, institutional and industrial buildings have led to the development of various specialized floor sweeping and scrubbing machines. One class of such equipment is comprised of rotary broom sweepers, in which a rotating cylindrical brush contacts the floor and throws loose debris into a collection hopper which is periodically emptied. Another class is comprised of scrubbers. These machines apply cleaning solution from an onboard tank to the floor, agitate it with one or more rotating brushes to loosen soilage that is adhered to the floor and suspend it in the cleaning solution. Then they pick up the soiled solution with a vacuum pickup squeegee and store it in an onboard tank for later emptying. The various uses to which buildings are put result in many different floor conditions, some of which are best cleaned by sweepers and some by scrubbers. Many buildings require both sweeping and scrubbing at different times or in different areas. This necessitates investing in both a sweeper and a scrubber, which is a substantial expense.
To reduce this investment there have been combination machines built which could perform both sweeping and scrubbing functions. One class of these is comprised of sweepers with scrubber attachments. In these there is a prime mover which is equipped with a dry debris hopper and a dust control system, in which configuration the machine functions as a sweeper. On occasion the hopper may be removed and a separate scrubber attachment installed in its place. The attachment will contain a tank for supplying cleaning solution to the floor, usually a specialized scrubbing brush, and a vacuum pickup squeegee for removing soiled solution from the floor. The attachment will also provide a tank for storing the soiled solution. These machines are effective and ar widely used. However, the cost of the separate scrubber attachment is substantial, and the time involved in changing from one mode of operation to the other adds to the operating expense.
There are also so called sweeper-scrubbers, which are machines that can either sweep or scrub without removing or adding any parts. These typically have a sweeping brush that throws debris into a hopper, and one or more other brushes that scrub. The sweeping brush and the scrubbing brush are arranged in tandem, and the added elements increase the length of the machine, with an attendant loss in maneuverability. There may be some compromise in performance; for example, the sweeper hopper may be smaller than customary, or dust control may not be provided. And the added elements increase the cost of such machines over the cost of single purpose scrubbers and sweepers.
The present invention overcome the above described shortcomings of the prior art and offers other advantages by achieving the following objects:
1. One machine which can function as a sweeper complete with dust control or as a floor scrubber complete with vacuum squeegee pickup of scrub water without removing or adding any parts.
2. One machine which can be changed from operating in sweeping mode to operating in scrubbing mode or vice versa by a machine operator at any time by manipulating one or a few conveniently located controls.
3. A compact machine for maximum maneuverability, which provides the functions of a sweeper and a scrubber in one machine which is essentially no longer than an equivalent single purpose sweeper or scrubber while retaining typical hopper and tank volumes.
4. A combination sweeping and scrubbing machine which does not require both a brush for sweeping and another brush or brushes for scrubbing, but which has one brush that is the main cleaning tool in both the sweeping mode and the scrubbing mode.
5. A combination sweeping and scrubbing machine which uses a single debris hopper to receive and store debris in both sweeping and scrubbing modes. When in the scrubbing mode this hopper functions to receive debris and scrub water from the floor and to retain the debris while returning the scrub water back to the floor so that no vacuum pickup is needed in said debris hopper to remove water from it.
6. A combination sweeping and scrubbing machine which is equipped with only one tank for maximum compactness, this one tank serving to hold cleaning solution to be dispensed to a floor to be scrubbed and also to receive soiled cleaning solution that is recovered from the scrubbed floor by a vacuum pickup squeegee.
7. A combination sweeping and scrubbing machine which in its scrubbing mode recycles a substantial part of its supply of scrub water by applying it to the floor more than once, and thereby extends its run time as compared to a machine which only uses its supply of scrub water once.
8. A single tank for a combination sweeping and scrubbing machine in which the lower portion of the tank is made to serve as a sediment sump by placing the outlet somewhat above the bottom of the tank.
9. A combination sweeping and scrubbing machine which uses fewer parts than prior art sweeper-scrubbers, and consequently has a lower manufacturing cost and fewer service problems.